This application relates to U.S. patent application Ser. No. 08/581137, "Electrocapillary Display Sheet" and U.S. patent application Ser. No. 08/643,678 "Electrocapillary Color Display Sheet" (All Common Assignee).
This invention relates to an electrocapillary color display sheet and more particularly concerns an electrocapillary color display sheet which utilizes a plurality of sets of droplets of dyed polar liquid in between two transparent sheets. By selectively applying an electric field directly to each droplet of each set, each droplet in each set of droplets can be selectively expanded to occupy a space in a size of a pixel in order to create a colored pixel of an image.
The suggested display devices, in sheet form, comprise a thin sheet which has many attributes of a paper document. It looks like paper, has ambient light valve behavior like paper (i.e. the brighter the ambient light, the more easily it may be seen), is flexible like paper, can be carried around like paper, can be written on like paper, can be copied like paper, and has nearly the archival memory of paper.
There have been different approaches to make an electronic display sheet such as U.S. Pat. No. 4,126,854 titled "Twisting Ball Panel Display" in which the display panel is comprised of a plurality of spherical particles which have different colors on each hemisphere. Depending on the direction of an electric field applied to each spherical particle, one of the hemispheres will be displayed. In this approach, for a black and white display sheet, each ball has a black hemisphere and a white hemisphere. The black and white hemispheres of the spherical particles can be selected in such a manner to display a desired image or text.
It is an object of this invention to provide a different approach to make an electronic color display sheet.